Minnesota, where “a soldier of the Islamic State” stabbed nine people in a mall on Sept. 17, is the focus of the largest ongoing terrorism investigation in the U.S.

Since 2014, 11 Somali-Minnesotans have been charged in an alleged plot to travel to Syria and join ISIL. Two were charged in absentia after they left the U.S. — among at least five young Minnesotans federal officials say successfully joined the terror organization. Six others pleaded guilty and three were convicted in May.

A man wearing a private security company uniform stabbed eight people at a Minnesota mall before an off-duty police officer shot him dead, authorities said.

Previously, several dozen men and women from Minnesota joined the terror group Al-Shabab in Somalia, prompting the Justice Department to select Minneapolis as one of three federal pilot cities for a project to counter terror recruitment.

Before the mall attack on Sept. 17, however, the feds’ focus had been on Minnesotans trying to leave the country, not attack civilians here.

The Amaq News Agency, ISIL’s media wing, said that Dahir A. Adan, 22, carried out the mall attack as an “operation in response to calls to target the citizens of the crusader coalition.”

As it continues to lose territory in Syria, Iraq and Libya, ISIL is calling on its supporters around the globe to stay at home and carry out attacks there.

ISIL has “lowered the bar for what they consider a successful attack,” counterterrorism analyst Thomas Joscelyn said. “They’ve been advocating people lashing out whatever way they can: Pick up a knife, a machete or drive a car into them. Do whatever they can to cause havoc. As long as it creates terror and generates headlines it’s a success for them.”

FBI Director James Comey, in a June visit to Minneapolis, said the number of Americans seeking to travel to join ISIL has decreased, but the number of ISIL-related investigations the FBI is opening on the homefront is on the rise, with roughly 1,000 cases open. Comey said the FBI is investigating cases in all 50 states.

“A more disturbing possibility is people are starting to stay home because they know we might catch them if they travel and they’re looking to do things on behalf of the Islamic State at home,” Comey said.

“Under the leadership of Obama & Clinton, Americans have experienced more attacks at home than victories abroad. Time to change the playbook! … Saturday’s attacks show that failed Obama/Hillary Clinton polices [sic] won’t keep us safe! I will Make America Safe Again! … Terrible attacks in NY, NJ and MN this weekend. Thinking of victims, their families and all Americans! We need to be strong!”